Few natural barriers and harsh climate
China, Russia
Russia's withdrawal from the war.
Russia developed its own nuclear program, and was aided by espionage.
The separation of the US from European, Asian and African interference because of separation by the Atlantic and Pacific Oceans the IS to grow without outside interference.
slavery and editorship
Provided a system for governing the Western Territories that aided the nation's expansion.
The Seven Year War was fought between Great Britain and France. Russia and Spain aided France and Prussia and Portugal aided Great Britain.
The services of Privateers were purchased by monarchs during war time. Privateers were useful because they were an expansion on the countries military and they were able to carry weapons and trade goods without being attacked by an enemy ship.
self pollination are aided by many factors one of which iz water,air insect like am beez
globalization of cultures and economics
Agriculture and trade are two major factors that aided the development of complex social systems. The ability to produce surplus food through agriculture allowed for larger populations and specialization of labor, while trade helped facilitate communication, exchange of goods, and formation of interconnected networks.
The California Gold Rush was a major factor in expansion west of the Mississippi. That westward expansion was greatly aided by the completion of the Transcontinental Railroad in 1869, and passage of the Homestead Act in 1862.